1. Field of the Invention
The invention relates to mechanically operated umbrellas having an axially offset support.
2. Background Information
Café umbrellas commonly use an axially offset support pole and a laterally extending support arm to hold up a collapsible canopy. A variety of mechanisms have been proposed for mechanically opening and closing the canopy. Some of these mechanisms are configured to move the canopy closer to the support pole as it is closed so as to provide a more compact and attractive storage arrangement.
Some known mechanisms for opening and closing a café umbrella require a carriage or traveler that is attached to one end of a movable arm and that slides along a fixed arm. These arrangements are problematic in that avoiding excess sliding friction may involve either lubricating an external surface with materials that can soil clothing, or employing slotted support arms and internal carriages that can post a pinch hazard. Examples of such mechanisms have been taught by Glatz in U.S. Pat. No. 5,785,069, by Goldwitz in U.S. Pat. No. 6,988,504, by Ma in U.S. Pat. No. 6,321,763, and by Vennick in U.S. Pat. No. 5,116,258.